Electronic and thermoelectric transport properties for an armchair graphene–silicene–graphene heterojunction modulated by external field

•The maximum value |SC||SC| for an armchair-edge GSG heterojunction can reach 2000 μV/K2000 μV/K.•The charge Seebeck coefficient for armchair-edge GSG heterojunctions can be improved by one order of magnitude compared with that for zigzag-edge GSG heterojunctions.•The transmission coefficient and the charge Seebeck coefficient for GSG heterojunction can be effectively modulated by effective spin–orbit coupling λSOλSO and the potential energy V0V0.

We analytically investigate effective spin–orbit coupling (SOC) and potential energy on electronic and thermoelectric transport properties for a graphene–silicene–graphene (GSG) heterojunction with armchair-edge nanoribbons using nonequilibrium Green's function method. The calculation shows that the transmission coefficient T   and the charge Seebeck coefficient SCSC for armchair-edge GSG junctions display the oscillatory behavior and depend sensitively on both effective SOC λSOλSO and the potential energy V0V0. Compared with zigzag-edge GSG heterojunctions, armchair-edge GSG heterojunctions are found to posses superior thermoelectric performance, their charge Seebeck coefficients can be improved by one order of magnitude.